Three point lighting: key light
In this series Ian Hider, BBC Academy trainer, covers the basics of three point lighting and explains why the key light is of such importance, what it will achieve and where it can be placed.
In a traditional interview set up the key is your main light source. Its positioning has a big effect on how your interviewee looks. If you position it close to your interviewee's eyeline nearly all of their face will be lit. Moving the key away from the eyeline introduces more shadow onto the face.